Up on the rooftop of a small building in Santa Monica - lots of sunshine around, only a few clouds, just another perfect California day, with a view clear to the Pacific where the surfers ride - Josh Brolin is smoking a cigarette and sweating. He's sweating because he's an athletic guy and just got back to his office after working out, before heading upstairs and into the heat, to sweat some more. He's smoking because he just can't seem to quit.

"Yeah," he says, holding the damn thing out, considering it and taking another puff. "I'm an idiot."

It's not a point you can argue, of course. On the other hand, he's pretty much full of those kinds of off-slant combinations. Just look at him. The thick, full head of hair at age 44. The strong, square jaw that you just know can take a punch. The panty-dropper lips and wide-open smile. The chin stubble, just right. The bulging muscles beneath a trim, black T-shirt, just right. Almost everything, just right, in a rough-and-tumble, rugged way, which makes it kind of great that he tends to get cast against type, in movies like Oliver Stone's 'W.' (2008, as George Bush) and 'Milk' (2008, as murderer Dan White, which earned him an Oscar nomination), as well as expectedly dead-on, in films like 'No Country for Old Men' (2007, as a doomed cowpoke), 'American Gangster' (2007, as a corrupt narc), and, most recently, 'Gangster Squad,' as a police officer charged with ridding Los Angeles of the Mob, in which he kills everything and anybody that stands in his way, making him both hero and antihero.

But for such a cool-looking, no-nonsense-appearing, action-oriented-seeming guy - he surfs, skydives, motorcycles, races cars, bungee-jumps, all that kind of daredevil stuff - he is, in fact, a class-A nerdo-weirdo. To take just the most glaring example: In his spare time, Brolin likes to write poetry, prose, and plays. Can you imagine? Poetry, prose, and plays! And, truth be told, when it comes to poems, he's written hundreds of them, if not thousands, starting when he was eight, continuing even through the period he was in a hardcore surf gang called the Cito Rats and dabbled in heroin. And if one subject is at the heart of them all, it's his mother, the late Jane Agee, who divorced Brolin's dad, the actor James Brolin, when Josh was 16, crashed into a tree on her son's 27th birthday, and died the next day. He wrote about her before her death; he's written about her since her death. She's on his mind a lot.

"She was a different kind of lady," he says, the gravel and twang in his voice slowly coming out. "She was very extreme, in every kind of way, and sometimes I'll write about extreme situations we were in, like us drinking in a church together, or her pulling a gun on some dude. She was a real character. Her maternal force wasn't typical at all."

And then he doesn't say more about her for a good long while.

He's got other stuff on his mind. Just last night, some wacko kid in Colorado marched into a movie theater and began blasting away, killing 12, injuring 58 (and, in the aftermath, forcing Warner Bros. to push back 'Gangster Squad's' release date so it could come up with an alternative to the existing ending, which featured its own movie-theater massacre). Right now, all Brolin can think about is the tragedy. "I'm just fucking stunned," he says. "I'm beyond blown away. When I woke up to that, I immediately started crying, and the stresses of my life immediately became irrelevant, meaningless confetti. I mean, fucking Christ." He pauses, squinting at the sun. "It's weird, though. I feel a modicum of pain for the perpetrator. What happened to this kid to put him in that position? Is he truly mentally deranged? Was he born that way? Is he a John Wayne Gacy? A Ted Bundy? Is it about abuse? Neglect? An insatiable need for instant gratification? Is it about - you know what I mean? I go through this whole plethora of possibilities."

That he does, and it seems entirely characteristic of him. He's intense like that, and curious. He wants to know what's going on inside, where the normal so often combines with the abnormal to produce the unexpected. He's had to deal with this in his own life, many times. In 2006, for instance, two weeks before filming started on 'No Country for Old Men' - the movie that made him more than just a great character actor - Brolin was zipping around L.A. on his Ducati when he collided with a car, looped through the air, and broke his collarbone, putting himself in the position of having to lie to the Coen brothers about his health in order to keep the job. At the time, his wife, the actress Diane Lane, said to him, "Why do you always make it so difficult for yourself?" as if he brought on the accident himself, like maybe it was no accident at all.

Brolin thinks about this now, the unexpected possibility of that being true. He kind of grimaces. "It does seem that way," is all he can think to say. And he's right. For whatever reason, it really does seem that way.